[" (c) "1],[" Il."tan20^(@)tan40^(@)tan60^(@)tan80^(@)=]

tan20^(@)tan40^(@)tan80^(@)

tan20^(@)tan30^(@)tan40^(@)tan80^(@)=1

tan 20^(@) tan 40^(@) tan 60^(@) tan 80^@=

tan 20^(@) tan 40^(@) tan 80^(@) = tan 60^(@)

Prove that: tan20^(@)tan40^(@)tan60^(@)tan80^(@)=3

Prove that :tan20^(@)tan40^(@)tan60^(@)tan80^(@)=3

tan20^(@)-tan80^(@)+sqrt(3)tan20^(@)tan80^(@)=

(tan60^(@)-tan30^(@))/(1+tan60^(@)tan30^(@))=tan30

Prove that tan20^(@)tan40^(@)tan80^(@)=tan60^(@)

Prove the following: (i) "tan" 20^(@) tan 40^(@) tan 60^(@) tan 80^(@)=3 (ii) "tan" 20^(@) tan 40^(@) tan 80^(@)="tan" 60^(@) .